I decided to use dictionaries to populate multiple tableViews with API calls as opposed to using arrays and async await to reduce load times. I call all of my API's in a background thread asynchronously, giving each dictionary an incremented index from 0 up, and when all the API calls are done I sort the dictionary as such:
let sortedDictionary = dictionary.sorted {
return $0.key < $1.key
}
Then I populate my tableViews; much faster than running the API calls in sequence. Now I have to somehow reorder the tableViews upon deleting a row like you would to a standard array (I have a scrollView with several tableViews, and another tableView that has a row for each tableView; this second tableView is the one which I am deleting rows). This is my attempt, but something in my logic is off, or I'm missing something:
func tableView(_ tableView: UITableView, commit editingStyle:
UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete{
//delete object from dictionary
self.dictionary.removeValue(forKey: indexPath.row)
for i in indexPath.row...dictionary.count-1{
if i == dictionary.count-1{
//remove last index in the dictionary at end of loop
self.dictionary.removeValue(forKey: i)
} else{
//increment all dictionary indices past the deleted row down one
let j = i i
let value = dictionary[j]
guard let value = value else {return}
self.dictionary.removeValue(forKey: j)
self.dictionary.updateValue(value, forKey: i)
}
}
}
}
It seems that I'm running into a null here:
guard let value = value else {return}
Is this not the correct way to store a dictionary value?
let value = dictionary[j]
Any help is appreciated. Thanks!
CodePudding user response:
I resolved the issue and formatted it into a templated function so that it can be used on multiple dictionary models. As comments above mentioned, dictionaries can simply be sorted, but this is another way to do it:
func deleteRows<T>(indexPath: IndexPath, dictionary: inout Dictionary<Int, T>){
if indexPath.row == dictionary.count-1{
//if its the last object in the tableView, delete and return
dictionary.removeValue(forKey: indexPath.row)
return
}
//store last object in dictionary
let lastIndex = dictionary[dictionary.count-1]
for i in indexPath.row...dictionary.count-1{
if i == dictionary.count-2{
//remove last object in the dictionary at end of loop
dictionary.removeValue(forKey: dictionary.count-1)
//append last object
guard let lastIndex = lastIndex else {return}
dictionary.updateValue(lastIndex, forKey: dictionary.count-1)
} else if i < dictionary.count-1{
//increment all dictionary indices past the deleted row down one
let value = dictionary[i i]
guard let value = value else {return}
dictionary.updateValue(value, forKey: i)
}
}
}